Various devices are known for digging up furrow slices to extract such root crops therefrom. These devices, generally, comprise a screen conveyor mounted behind a plow within the body of a vehicle which may be self-propelled or towed, the plow projecting from the open front of the vehicle while the conveyor delivers the harvested roots at its rear to a bin on the same or on a following vehicle.
It has already been proposed (see Pat. No. 35,146 of the German Democratic Republic) to mount such a screen conveyor for pivotal movement about a horizontal axis whose location is fixed with reference to the vehicle, thereby allowing a tilting thereof under the control of a hydraulic jack. G.D.R. Pat. No. 65,490 describes an arrangement for controlling the tilt of a plow, mounted at the front end of a trailer-borne frame which carries the forward support roller or rollers of the conveyor, with the aid of a pilot member carried by an associated tractor and rotatable with reference to the trailer body. An hydraulic linkage connecting a conveyor-and-plow assembly with rollers engaging the furrow slices is known from G.D.R. Pat. No. 82,230. Pat. No. 1,214,031 of the German Federal Republic describes a hydraulic hoist for elevating the plow assembly with reference to the vehicle body.